Reinforced Earth 50th Publication

Newry Bypass

Shrub Hill Retail Park

This major roads PFI scheme is for the Design, Build, Finance and Operation of 5 separate schemes. The £250 million project involved the upgrade of 21km of the A4 between Dungannon and BallyGawley and 12km of new dual carriageway on the A1 from Beechhill to Cloghogue. Reinforced Earth Company (RECo) were approached to undertake the specialist design and supply over 6,000 precast facing panels and 2.5km of copings on 20 structures on 3 different schemes on the project over a 2-year period. The walls and abutments were constructed using selected granular fill with galvanized steel soil reinforcement. The walls were faced with TerraQuad concrete panels with a vertical rib finish. The bridge loads were designed to be supported in one of two ways; either the deck was supported on columns passing through the Reinforced Earth end walls, or the integral bridge deck was fully supported on the Reinforced Earth abutments. The versatile nature of Reinforced Earth allowed both support principles to be used depending on the site requirements.

As part of a retail development, a new canal bridge was required to replace an existing masonry structure. The conforming scheme for the bridge comprised a simply supported single span deck on piled abutments. As an alternative, Reinforced Earth Company (RECo) proposed an arch structure. The arch was required to accommodate a clearance envelope for the navigable waterway and provide pedestrian clearance along the towpath. The solution adopted comprised a buried arch structure founded on a piled strip foundation. The precast segmental arch was erected as a three pinned structure. However, due to the minimal fill cover over the crown, the structure was made continuous across the crown joint with an in-situ concrete stitch to form a two pinned structure. The spandrel walls and wingwalls were formed in Reinforced Earth using a galvanized steel mesh facing system. The completed walls were subsequently clad in brickwork to meet the aesthetic requirements of the project. Erection of the arch units was completed in just two days. The combination of Reinforced Earth Company’s arch and masonry clad retaining walls provided the Contractor with a cost effective alternative to the conforming scheme. The finished project was shortlisted for the Institution of Civil Engineers’ Midlands Award in 2003.

(photo courtesy of David Scott PhotographyMacrete Ireland Ltd)

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